1. Field of the Invention (Technical Field)
The invention relates to nuclear reactor source and system apparatus for generating power and propulsion in space; and a method of using such apparatus.
2. Background Art
Bimodal space nuclear reactor power and thermal propulsion systems theoretically could enable a variety of space missions. Examples of such missions might include a new generation of wide-band surveillance satellites, planetary exploration, global air traffic control, transport of payloads to higher orbits, and repositioning of satellites in orbits.
Such mission requirements cannot presently be met. Conventional bimodal (or hybrid) solar electronic or chemical propulsion systems are slow, have limited maneuvering capabilities, and have relatively large sizes and masses.
While electric propulsion systems are capable of generating high average specific impulse (I.sub.sp), their thrust capability is limited. Electric bimodal missions could require tens of kilowatts, up to 10 years duration, thrust of up to thousands of Newton and Isp of 600 to 850 seconds, for hundreds of hours.
U.S. Pat. No. 5,106,574 to El-Genk, et al., entitled Nuclear Reactor Refuelable in Space, issued Apr. 21, 1992, discloses a sectored reactor with fuel pellets, thereby enabling fueling or refueling in space or on the ground, as well as operational redundancy.
Morley and El-Genk, "Passive Decay Heat Removal in the PeBR Concept for Nuclear Thermal Propulsion," Proc. 9th Symp. on Space Nuclear Power Systems, CONF-920104, M.S. El-Genk and M.D. Hoover, eds. American Institute of Physics, New York, N.Y., Conference Proc. No. 246, 3:955-966 (1993), discusses passive decay heat removal after shutdown. Liscum-Powell, J. and M.S. El-Genk, "Neutronic Analysis and Design Optimization of the Pellet Bed Reactor for Bimodal Applications," Proc. 11th Symp. Space Nuclear Power Systems, CONF-940104, M.S. El-Genk, ed., American Institute of Physics, New York, N.Y. (to be published in 1994) discusses bimodal reactors design of pellet bed reactor for bimodal space application.
Juhasz, A., M.S. El-Genk, and W. Harper, "Closed Brayton Cycle Power System with a High Temperature Pellet Bed Reactor Heat Source for NEP Applications," Proc. 10th Symp. on Space Nuclear Power and Propulsion, CONF-930103, M.S. El-Genk and M.D. Hoover, eds., American Institute of Physics, New York, N.Y., Conference Proc. No. 271 2:1055-1064 (1993) discusses sectored reactor core structure in combination with closed cycle gas turbine engines.
El-Genk, et al., "High Performance Bimodal Space Nuclear Power and Propulsion System" Proc. 11th Symp. Space Nuclear Power Systems, CONF-940104, M.S. El-Genk, ed., American Institute of Physics, New York, N.Y. (to be published in 1994) details design approaches for potential bimodal power systems.